1. Field of the Invention
The present disclosure generally relates to rheology modifying agents useful for modifying the rheology of slurries. More particularly, the present disclosure relates to rheology modifying agents useful for modifying the rheology of lime slurries and magnesium oxide slurries.
2. Description of the Related Art
Slurries of lime and magnesium oxide are commonly added to hot lime and warm lime softeners to treat water hardness (i.e., remove hard water ions) and to assist in silica removal. If these ions are not removed from the water, the subsequent equipment coming into contact with the water will obtain hard water deposits, and fouling of the equipment will occur. Hard water fouling can occur in, for example, heat exchangers, evaporators, and boilers. Heat exchangers, evaporators, and boilers can be used to produce hot water or steam that can be used in various processes, such as hydrocarbon production and power generation. Further, lime and magnesium oxide slurries can also be added to scrubbers to assist with the scrubbing of acid gasses, such as SO2, H2S, and CO2. Magnesium oxide slurries can be used for adjusting pH during waste water treatment.
Feed lines are used to transport the slurries to the various pieces of equipment used in the processes. Without proper treatments for the lime and magnesium oxide slurries, the lime and magnesium can form deposits in the feed lines, thereby reducing the slurry feed flow, and eventually plugging or clogging the feed line. The hardened deposits in the feed lines are typically removed or dissolved by cleaning the feed lines with acids, such as HCl, which is not safe or easy to handle. Moreover, such an acid treatment requires special procedures for waste disposal.
Prior art methods used to clean feed lines are thus dangerous, costly, and require extended periods of system down time. When a slurry feed line becomes clogged, the entire operation needs to be shut down, the feed lines need to be taken off-line, and subsequently cleaned with the acid. In certain processes, these steps must be repeated, sometimes as frequently as once a week, thereby greatly increasing the total time needed to achieve the intended goal of the overall process, such as hydrocarbon production.